Ventilation apparatus for seat

ABSTRACT

A ventilation apparatus for a seat in which a positive temperature coefficient (PTC) heater is equipped in the ventilation apparatus which blows air to the seat in order to prevent overheating as well as to reduce heat loss. The ventilation apparatus includes a seat having a back and a seating section each of which has a discharge passage which discharges air toward a user. A blower is disposed in each discharge passage of the seat. A PTC heater is disposed inside each blower, and heats air that is being blown. A control unit simultaneously or individually controls the blowers and the PTC heaters. Accordingly, heating efficiency is improved and safety is increased.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Korean Patent Application No.10-2011-0122068, filed Nov. 22, 2011, the entire contents of which arehereby incorporated by reference herein.

FIELD OF THE INVENTION

The present invention relates, in general, to a ventilation apparatusfor a seat and, more particularly, to a ventilation apparatus for a seatin which a positive temperature coefficient (PTC) heater is equipped inthe ventilation apparatus which blows air to the seat in order toprevent overheating as well as to reduce heat loss.

BACKGROUND

In general, a seat of a vehicle serves to provide a cozy feeling ofseating using a cushion.

Recently, in response to the trends of consumers who demand conveniencein addition to basic functionality for vehicle parts, a variety ofconvenience devices are being equipped in a vehicle seat.

Among such convenience devices for a seat, most widely used is aseat-warming apparatus in which heating wires are disposed in the seatin order to provide warmth while driving in winter. Such a seat-warmingapparatus is applied to seats of a variety of vehicles, since there aresignificant difficulties in designing and construction. However, theability of the heating wires to make a user warm is limited.

In order to solve this problem, an approach in which a cooler isdisposed in the seat and a thermoelement is disposed in the cooler inorder to supply heated air to the seat is used. However, when heatingthe air using the thermoelement, there is a problem in that a separateoverheat-preventing means is essentially needed in order to preventdamage due to overheating.

In addition, when the thermoelement is used, there is another problem inthat a certain amount of air is discarded attributable to thecharacteristics of the thermoelement.

SUMMARY

Accordingly, the present invention has been made keeping in mind theabove problems occurring in the related art, and the present inventionis intended to propose a ventilation apparatus for a seat in which apositive temperature coefficient (PTC) heater is equipped in theventilation apparatus which blows air to the seat in order to preventoverheating as well as to reduce heat loss.

In order to achieve the above object, according to one aspect of thepresent invention, there is provided a ventilation apparatus for a seatwhich includes a seat comprising a back and a seating section, each ofthe back and the seating section having a discharge passage whichdischarges air toward a user; blowers each disposed in a correspondingdischarge passage of the seat; PTC heaters each disposed inside acorresponding one of the blowers, the PTC heaters heating air that isbeing blown; and a control unit which simultaneously or individuallycontrols the blowers and the PTC heaters.

In an exemplary embodiment, each of the blowers may include a housingand a temperature sensor disposed inside the housing, the temperaturesensor detecting a temperature of air which is taken in and transferringthe detected temperature to the control unit.

In an exemplary embodiment, the temperature sensor may be disposedbetween a blower fan disposed inside the blower and a corresponding oneof the PTC heaters.

In an exemplary embodiment, the control unit may control a rate at whichthe blower fan rotates and power which is supplied to the PTC heaterdepending on the temperature which is transferred from the temperaturesensor.

In an exemplary embodiment, the control unit may perform control so thatone of the PTC heaters which is disposed in the back 1 a is set to ahigher temperature when the PTC heaters are operated, and so that one ofthe blower fans which is disposed in the back rotates at a slowed-downrate when no PTC heaters are operated.

In an exemplary embodiment, each of the blowers may include a connectingduct in a predetermined portion thereof, the connecting duct beingconnected to a corresponding one of the discharge passages such that allof air that has passed through a place in which a corresponding one ofthe PTC heaters is disposed is supplied to a corresponding one of thedischarge passages.

In an exemplary embodiment, each of the PTC heaters may include a PTCdevice connected to an external power source to receive power therefrom;and heat exchange fins disposed on both sides of the PTC device.

In an exemplary embodiment, each of the PTC heaters may further includea connector electrically connected to the PTC device, the connectorbeing formed in a place of the housing which forms an outer surface ofthe blower, and the PTC heater being disposed in the place of thehousing.

According to embodiments of the invention, unlike the ventilationstructure of the related art which uses heat wires, the ventilationapparatus for a seat does not need an overheat-preventing meansattributable to the characteristics of the PTC heater, thereby reducingthe number of parts and improving safety.

While the thermoelement of the related art which uses heat wires wastesa certain amount of heat, the ventilation apparatus for a seat of theinvention uses all air that is being blown for heating or ventilation,thereby improving efficiency.

Furthermore, it is possible to simultaneously or individually controlthe heating and ventilation of the back and the seating section and tocontrol the blower fans and the PTC heaters depending on the temperaturethat is detected by the temperature sensors, each of which is disposedbetween a corresponding blower fan and a corresponding PTC heater,thereby improving efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and other advantages of thepresent invention will be more clearly understood from the followingdetailed description when taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 is a configuration view schematically showing a ventilationapparatus for a seat according to an exemplary embodiment of theinvention;

FIG. 2 is a perspective view of the blower shown in FIG. 1; and

FIG. 3 is a cross-sectional view of the blower shown in FIG. 1.

DETAILED DESCRIPTION

Reference will now be made in greater detail to a ventilation apparatusfor a seat according to an exemplary embodiment of the invention withreference to the accompanying drawings.

FIG. 1 is a configuration view schematically showing a ventilationapparatus for a seat according to an exemplary embodiment of theinvention, FIG. 2 is a perspective view of the blower shown in FIG. 1,and FIG. 3 is a cross-sectional view of the blower shown in FIG. 1.

As shown in FIG. 1 to FIG. 3, the ventilation apparatus for a seataccording to one exemplary embodiment of the invention includes a seat 1which includes a back 1 a and a seating section 1 b, blowers 10 whichare mounted on the back 1 a and the seating section 1 b, and positivetemperature coefficient (PTC) heaters 20 each of which is disposedinside a corresponding blower 10 to heat air that is being blown. Alsoprovided is a control unit which controls the blowers 10 and the PTCheaters 20. Although it is described by way of example that the seat 1is disposed inside the vehicle, the present invention is not limited tothe vehicle seat but is applicable to all sorts of seats.

Discharge passages 2 a and 2 b are formed inside the back 1 a and theseating section 1 b. Air that is forcibly blown by the blowers 10 isintroduced into the discharge passages 2 a and 20 b, which in turndischarge the air toward users.

Each blower 10 includes a housing 11, a blower fan 13 and a connectingduct 14. The housing 11 has an inner storage space defined therein, andhas an inlet in a side portion thereof. The blower fan 13 is disposed inthe inlet side of the housing 11 in order to take in and forcibly blowouter air. The connecting duct 14 is provided in a predetermined portionof the housing 11. The PTC heater 20 is disposed in an intermediateportion of the passage through which the air which is forcibly blownpasses. A temperature sensor 12 is disposed in the passage through whichthe air that is blown is guided, between the blower fan 13 and the PTCheater 20.

The control unit 30 receives a temperature signal from a temperaturesensor 12 which detects the temperature of the air that is blown by theblower fan 13, and controls the rate at which the blower fan 13 rotatesand the amount of heat which the PTC heater 20 generates. That is, thecontrol unit 30 controls power that is supplied to the blower fan 13 andthe PTC heater 20. It is preferred that the control unit 30 controls thecomponents such that the temperature of the PTC heater 20 which isdisposed in the back 1 a is set to be higher when the PTC heater 20operates, i.e. at the time of heating. In contrast, is preferred thatthe control unit 30 control the components such that the rate at whichthe blower fan 13 disposed in the back 1 a is slowed when no PTC heaters20 operate, i.e. at the time of blowing. It is possible to freely adjustthe amount of heat which the PTC heaters 20 generate and the rate atwhich the blower fan 13 rotates at the time of heating and blowing atthe request of the user.

Each PTC heater 20 includes a PTC device 21, heat exchange fins 22 and aconnector 23. The PTC device 21 is connected to an external power sourceand radiates heat when receiving power from the external power source.The heat exchange fins 22 are mounted on both sides of the PTC device21. The connector 23 is electrically connected to the PTC device 21,with one portion of the connector 23 being exposed to the outside andconnected to the external power source. The PTC device 21 is asemiconductor device which experiences a sharp increase in electricalresistance when its temperature becomes equal to or higher than a Curietemperature (about 180° C. to 200° C.). The PTC device has the functionof self-temperature control to maintain a predetermined heatingtemperature irrespective of surrounding temperatures when a voltage isapplied thereto. Consequently, electrical resistance increases at apredetermined temperature (about 180° C. to 200° C.) or higher and theamount of current decreases, thereby lowering the temperature of heat.

The connecting duct 14 is provided in a predetermined portion of theblower 10, in particular, in a predetermined portion of the housing 11,such that all air which is forcibly blown by the blower fan 13 can besupplied to the discharge passage 1 a or 1 b through the PTC heater 20.The connecting duct 14 is connected to the corresponding dischargepassage 1 a or 1 b. Although it is preferred that the connecting duct 14be integrally formed in the housing 11, the connecting duct can beformed of a separate member, which is coupled to the housing.

The ventilation apparatus for a seat of this embodiment as configuredabove provides indoor air to the seat by taking in indoor air using theblower 10 and changing the number of revolutions per unit time of theblower 10 in summer. In winter, ventilation apparatus heats the seatusing the PTC heater 20 by sensing the temperature of air which is beingtaken in. The control unit for a seat is formed of one electroniccontrol unit (ECU), and can simultaneously or individually control theblowers 10 and the PTC heaters 20 disposed in the back 1 a and theseating section 1 b.

The control unit adjusts the rate at which the blower fan 13 rotates andthe amount of heat which the PTC heater 20 generates, depending onvalues which are set according to temperatures. In an example, when itis intended to heat the seat, the blower fan 13 is rotated while the PTCheater 20 is operated so that air which is forcibly blown by the blowerfan 13 is heated while passing through the PTC heater 20. All of theheated air is supplied to the discharge passages 1 a and 1 b through theconnecting ducts 14. The heated air which has been supplied to thedischarge passages 1 a and 1 b is discharged toward the user who issitting in the seat 1 so that heating is carried out. In addition, inthe case of heating, it is preferred for the temperature at which thePTC heater 20 disposed in the back 1 a generates heat to be set to behigher. However, it is also possible to set the temperature of one ofthe PTC heaters 20 to be higher or the temperatures of the PTC heaters20 to be the same as required by the user.

In another example, when only the blowing operation is intended for theseat, the operation of the PTC heaters 20 is stopped and only the blowerfans 13 are rotated so that air that has been forcibly blown by theblower fans 13 is supplied to the discharge passages 1 a and 1 b throughthe connecting ducts 14. The air that has been supplied to the dischargepassages 1 a and 1 b is discharged to the user who is sitting in theseat 1 so that the user feels cool because of the air that isdischarged. When the blowing operation is performed as described above,it is preferred for the blower fan 13 of the blower 10 which is disposedin the seating section 1 b to be rotated faster than the blower fan 13of the blower 10 which is disposed in the back 1 a. It is also possibleto control the blower fans 13 which are disposed in the back 1 a and theseating section 1 b so that one blower fan rotates faster than the otherblower fan 13 or both the blower fans rotate at the same rate.

In addition, since the present invention uses the PTC heaters 20,overheating is prevented owing to the characteristics of the PTC heaters20, thereby improving safety. It is also possible to reduce the numberof parts since no separate overheat-preventing means is required. EachPTC heater 20 is provided with the connector 23 which is exposed out ofthe housing 11 such that the PCT heater can be easily connected to theexternal power source.

Although the exemplary embodiments of the present invention have beendescribed for illustrative purposes, those skilled in the art willappreciate that various modifications, additions and substitutions arepossible, without departing from the scope and spirit of the inventionas disclosed in the accompanying claims.

What is claimed is:
 1. A ventilation apparatus for a seat comprising: aseat comprising a back and a seating section, each of the back and theseating section having a discharge passage which discharges air toward auser; blowers each disposed in a corresponding discharge passage of theseat; positive temperature coefficient heaters each disposed inside acorresponding one of the blowers, the positive temperature coefficientheaters heating air that is being blown; and a control unit whichsimultaneously or individually controls the blowers and the positivetemperature coefficient heaters.
 2. The ventilation apparatus of claim1, wherein each of the blowers comprises a housing and a temperaturesensor disposed inside the housing, the temperature sensor detecting atemperature of air which is taken in and transferring the detectedtemperature to the control unit.
 3. The ventilation apparatus of claim2, wherein the temperature sensor is disposed between a blower fandisposed inside the blower and a corresponding one of the positivetemperature coefficient heaters.
 4. The ventilation apparatus of claim2, wherein the control unit controls a rate at which the blower fanrotates and power which is supplied to the positive temperaturecoefficient heater depending on the temperature which is transferredfrom the temperature sensor.
 5. The ventilation apparatus of claim 4,wherein the control unit performs control so that one of the positivetemperature coefficient heaters which is disposed in the back 1 a is setto a higher temperature when the positive temperature coefficientheaters are operated, and so that one of the blower fans which isdisposed in the back rotates at a slowed-down rate when no positivetemperature coefficient heaters are operated.
 6. The ventilationapparatus of claim 1, wherein each of the blowers comprises a connectingduct in a predetermined portion thereof, the connecting duct beingconnected to a corresponding one of the discharge passages such that allof air that has passed through a place in which a corresponding one ofthe positive temperature coefficient heaters is disposed is supplied toa corresponding one of the discharge passages.
 7. The ventilationapparatus of claim 1, wherein each of the positive temperaturecoefficient heaters comprises: a positive temperature coefficient deviceconnected to an external power source to receive power therefrom; andheat exchange fins disposed on both sides of the positive temperaturecoefficient device.
 8. The ventilation apparatus of claim 7, whereineach of the positive temperature coefficient heaters further comprises aconnector electrically connected to the positive temperature coefficientdevice, the connector being formed in a place of the housing which formsan outer surface of the blower, and the positive temperature coefficientheater being disposed in the place of the housing.